Engine overheating after driving 10 minutes from cold

[microgerry]

Hi.
I have a 2.0 tdi in my 66 reg Ateca which has been playing up for the last three months.

When starting from cold the coolant temperature builds up past 90 then up through 115 when it starts to alarm on the display. It will then rise to nearly 130 with the engine losing power and becoming undriveable.

However, if I stop the car before it alarms(about 112), switch off for a couple of minutes and then restart the engine then the temperature will reduce again to 90 and stabilise. The rest of the journey no matter how long, will be ok.

Anybody have any ideas please?

 

[Tell]

Hi.
I have a 2.0 tdi in my 66 reg Ateca which has been playing up for the last three months.

When starting from cold the coolant temperature builds up past 90 then up through 115 when it starts to alarm on the display. It will then rise to nearly 130 with the engine losing power and becoming undriveable.

However, if I stop the car before it alarms(about 112), switch off for a couple of minutes and then restart the engine then the temperature will reduce again to 90 and stabilise. The rest of the journey no matter how long, will be ok.

Anybody have any ideas please?

Sort of sounds like the SCR regeneration is going wrong where it's trying to burn of the particles in an active regeneration rather than the passive one. Normally the fans cut in and cool the engine down when that process is running. I could be talking nonsense thou but certainly the engine bay temperature goes up during the process hence the fans running up. You get the burning smell, that's normal.

Normally passive regeneration occurs if you are taxing the car sufficiently but active regeneration occurs if it's judged that it needs it, so you get a little fire burning in the SCR with the fans running cooling it off. It tests whether it needs to do a regeneration every 200 miles or so.

What is SCR? | Diesel Technology Forum

Selective Catalytic Reduction (SCR) is an active emissions control technology system used in many advanced diesel engines.

www.dieselforum.org

If that process has gone defective then you need a dealer to sort it out. I can see if the fan(s) were not cutting in to cool the regeneration down then you might get the condition as described.

Obviously other things like radiator fluid etc. Feels like active regeneration and fan(s) not running up. Although if they are running up when stopped with heat bellowing out from the side of the car it's working . Only an idea thou...

I would also run an Obdeleven / VCDS scan looking at the error codes before delivering to the garage if you have the tools. May throw light on it... it will be what they do. If it was SCR it would tell you I reckon.

 

[microgerry]

Thanks Tell for that informative reply indicating a possibles cause of my problem. Let me add some more info to help with possible diagnosis.

Three months ago when this started happening I took it to my local independent VAG specialist who said the car did not show up any fault codes and suggested it may just be a defective temperature sensor. We were safe to continue driving the car until such time as the problem worsens and is happening a lot more often. Then we could return for further investigations.
Last week we covered about 600 miles in the car while visiting family in the North East and on Wednesday on the A1(M) we had to pull onto the hard shoulder as we were unable to travel more than 40 mph! After switching the car off for about 3 minutes the temp had dropped enough to continue our journey and get off the motorway at the first exit. When we arrived in Middlesborough I located a SEAT dealership for further help. My intention was to purchase a temp sensor and get it replaced once back home in North Wales.
Told the service manager about the symptoms and was told the most likely culprit would be the water pump not opening soon enough to begin cooling the hot engine. He said they had come across it before on this engine.

One final note is that the temp gauge is rising every day now after about ten minutes of driving. If I stop and lift the bonnet there is no excessive heat from the engine. The fans are running as the temp indicates 125 or more! So, is it safe to drive? I need to get it repaired asap but the guy in SEAT garage said if it's the pump it wouldn't show a fault code.

 

[Tell]

I did wonder about the valve and pumps. Father was a flight engines on flying boats in the war and he did all his car mechanics on the kitchen table... valves playing up to restrict water flow (saw a few of those being brought indoors... boiling hot water I think). 40 mph reckon is limp home mode which is what they switch to in distress (had that once when the turbo pipe blew off). Best to get it sorted asap since an overheating engine isn't what you want. Computers and audio is my baby not mechanics left that to the rest of the family.

 

[jheckstallsmith]

Hi @microgerry I am having the exact same problem with my Seat ATECA over the past 1-2 months - with identical inconsistencies and car behaviours. Was your issue diagnosed and solved? I need to get mine in ASAP. Cheers!

 

[microgerry]

Hi @microgerry I am having the exact same problem with my Seat ATECA over the past 1-2 months - with identical inconsistencies and car behaviours. Was your issue diagnosed and solved? I need to get mine in ASAP. Cheers!

Yes it was! Faulty waterpump. Had the pump and cambelt replaced with no further problems.
It's so annoying isn't it?

 

[jheckstallsmith]

Yes it was! Faulty waterpump. Had the pump and cambelt replaced with no further problems.
It's so annoying isn't it?

Ah, that is interesting and good to know so thank you. I will direct my garage to look at the water pump before anything else, in that case. Cambelt is due after 5 years or 80k miles and mine is a 16 reg. May I ask how the garage identified the water pump as the issue on yours and did they look at anything else (thermostat etc) - reason I ask is just in case it isn't the water pump on mine that's the issue. Cheers!

 

[microgerry]

Ah, that is interesting and good to know so thank you. I will direct my garage to look at the water pump before anything else, in that case. Cambelt is due after 5 years or 80k miles and mine is a 16 reg. May I ask how the garage identified the water pump as the issue on yours and did they look at anything else (thermostat etc) - reason I ask is just in case it isn't the water pump on mine that's the issue. Cheers!

Mine is a 66 reg so about the same age. We just had the cambelt done one year earlier than it was due.
SEAT Dealer diagnosed it from the symptoms I described and the independent VAG specialist who repaired it agreed and said they had replaced loads after such a short time. Something about a poor quality impellor on the pump apparently.

Very disappointed we had this expense after only four years.

 

[microgerry]

Hi @microgerry I am having the exact same problem with my Seat ATECA over the past 1-2 months - with identical inconsistencies and car behaviours. Was your issue diagnosed and solved? I need to get mine in ASAP. Cheers!

Hi
Did you ever get yours repaired? Was it another defective water pump?